There has been a renaissance in the use of cell biology techniques to study biological functions and mechanisms. This advance has been driven by the development of new fluorescent probes, more sensitive imaging systems and new techniques. Increased information has led to the realization that the cell is highly organized in ways that facilitate the interaction of different cellular factors to mediate biological function. These studies have greatly enhanced our basic understanding of the biology of infectious diseases, cancer, and development. Traditionally, the resolution obtainable by light based microscopy techniques is limited by diffraction to about half of the wavelength of the light utilized. More recently, several advancements in microscope technologies have allowed this diffraction limit to be overcome. To take advantage of these recent technological advances, we propose to purchase an OMX super-resolution microscope system built by Applied Precision Instruments of Issaquah, Washington. This system utilizes structured illumination to overcome the diffraction limits of normal light microscopy. At Northwestern University, the NIH supported research of many scientists requires fluorescent microscopy to characterize small viral and cellular structures within cells, which can mediate key biological functions. Therefore, it is critcal that the components of these structures and their relationships to one another be defined in the highest possible detail. As demonstrated with preliminary data included in the application, the OMX can deliver new insights into the spatial details of such structures including the nuclear lamins, desmosomes, and intracellular viral complexes. The OMX super-resolution microscope system will be housed in the outstanding Cell Imaging Core Facility at Northwestern, giving widespread access to this revolutionary imaging technology. There is currently nothing like this state-of-the-art technology in our Cell Imaging Core Facility or in the greater Chicagoland area. Therefore, this system will greatly enhance the NIH supported research of the Northwestern user group and similar types of research here and at nearby institutions. PUBLIC HEALTH RELEVANCE: Access to a super-resolution microscope will increase the capabilities and facilitate the cell biology research of the user group at Northwestern University and others in the region. This in turn will facilitate a greater level of productivity and advance f knowledge from NIH sponsored research at Northwestern University and the greater Chicago area.